In general, a grain conveying apparatus using air, which is divided into an air blowing type and an air suction type, conveys grains to a desired grain processing machine or storage.
For example, as the air blowing type, “Nozzle for Discharging Grains in Grain Conveying Apparatus Using Wind Pressure (Patent Document 1) and Device for Conveying Agricultural and Marine Products (Patent Document 2) have been proposed.
Patent Documents 1 and 2 disclose a structure for delivering the grains by using a fluid or air for conveying the grain and when the fluid or air moves while being in direct contact with the grains, the grains are damaged due to eddy current or collision and discharged together with foreign materials, and as a result, loss increases.
As another air blowing type, Wind Pressure Type Grain Elevator (Patent Document 3) and Delivery Apparatus Using Air Pressure (Patent Document 4) have been proposed.
Patent Documents 3 and 4 disclose a structure for separating foreign materials while moving the grains by blowing air. The grains are damaged due to impacts when the air and the grain come in contact with each other and impacts when the grains flow into a filtering mesh or a narrow outlet and discharged together with the foreign materials, and as a result, the loss increases.
Meanwhile, as the air suction type, Grain Suction Conveying Apparatus (Patent Document 5) has been proposed. In Patent Document 5, since the grains are conveyed by the suction force of the air, the damage of the grains is slight during conveying of the grains, but the grains which collide with a grain blocking body are scattered and dropped downward and the foreign materials having a relatively low specific gravity are discharged to an air inlet on the upper side in order to separate the grains from the foreign materials after conveying the grains. At this time, the grains which collide with the grain blocking body are damaged, and as a result, there is a problem that the grain collection rate is decreased. In addition, in Patent Document 5, there are problems that a structure of a separation container is complicated, a volume is large, manufacturing cost is expensive, and maintenance and management costs are increased